Catheterization and interventional procedures, such as, for example, angioplasty, catheterization, and the placement of stents, are commonly performed by inserting a hollow needle through the skin and tissue of a patient into the patient's vascular system. A guide wire is then often advanced through the needle and into the patient's blood vessel. The needle is then removed, enabling an introducer sheath to be advanced over the guidewire into the vessel, e.g., in conjunction with, or subsequent to, a dilator. A catheter or other device may then be advanced through a lumen of the introducer sheath and over the guidewire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.
In practice, the introducer sheath is often inserted into the patient's vasculature using the modified Seldinger technique. In the Seldinger technique, a needle is first inserted into the vessel and a guide wire then follows through the needle. Next, the needle is removed and a sheath/dilator combination is advanced over the guide wire. The dilator expands the puncture in the vessel to a size suitable to receive the distal end of an introducer sheath. After the distal end of the sheath is disposed within the vessel, the dilator and guide wire are removed, thereby allowing access to the vessel lumen or other body lumen via the inserted introducer sheath.
Upon completing the diagnostic and/or treatment procedure, the devices and introducer sheath are removed, leaving a puncture site in the vessel wall. One will appreciate that it is desirable to close the puncture site in vessel wall. Closing the wound can be difficult due to substantial bleeding that can occur through an open wound in a blood vessel. One method of closing the puncture site includes applying external pressure to the puncture site until clotting and wound sealing occur; however, the patient must remain bedridden for a substantial period after clotting to ensure closure of the wound. This procedure can be time consuming and expensive, requiring as much as an hour of a physician's or nurse's time. It also can be uncomfortable for the patient and may require that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Another method of puncture site closure is the use of bioabsorbable fasteners or sealing plugs. Bioabsorbable fasteners or sealing plugs can overcome many of the disadvantages associated with manual compression. Typically, these approaches rely on the placement of a thrombogenic and bioabsorbable material, such as collagen, at the superficial arterial wall over the puncture site. While potentially effective, this approach can suffer from a number of disadvantages. For example, it can be difficult to properly locate the interface of the overlying tissue and the adventitial surface of the blood vessel. Placing the plug too far from that interface can result in failure to provide hemostasis, and subsequent hematoma and/or pseudo-aneurysm formation. Conversely, if the plug intrudes into the artificial lumen, intravascular clots and/or collagen pieces with thrombus attached can form and embolize downstream, causing vascular occlusion. Also, thrombus formation on the surface of a plug protruding into the lumen can cause a stenosis, which can obstruct normal blood flow. Other possible complications include infection, as well as adverse reaction to the collagen or other implant.
Yet another approach for vascular closure includes the use of suture-applying devices. Conventional suture-applying devices are introduced through the tissue tract and advanced until a distal end of the device extends through the puncture site. One or more needles in the device are then deployed and used to draw suture through the blood vessel wall. Next, the suture is secured to provide closure of the puncture site. While suture-applying devices can overcome many of the difficulties associated with other puncture site closure devices and methods, locating the tissue surrounding a puncture site can be difficult using some suture-applying devices and methods. Some complications that may arise by misplaced or insufficiently anchored sutures include oozing, excessive bleeding, and potential knot loosening.